Polymer‐Based Superhydrophobic Coating Fabricated from Polyelectrolyte Multilayers of Poly(allylamine hydrochloride) and Poly(acrylic acid)

Abstract

Superhydrophobic films mainly based on poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) polyelectrolyte multilayer have been deposited onto cleaned glass substrate by a layer‐by‐layer dip coating method. 3 bilayers of the PAH and PAA was directly coated onto the substrate as an underlying layer for subsequent coating. Desired surface roughness on the polyelectrolyte bilayers was created by etching the bilayers in hydrochloric acid solution so as to create the open pore having suitable size at the surface. Then, nanoparticles such as SiO2 and TiO2 of various sizes were deposited onto the etched polyelectrolyte bilayers. Finally, the surfaces were further modified with semifluorinated silane followed by cross‐linking at 180 °C for 2 h to obtain desirable surface morphological features. The effect of etching time and addition of nanoparticles on surface morphology was investigated using an atomic force microscope (AFM). Wetting ability of the prepared film was determined by measuring water droplet contact angle using a goniometer. Adhesion between the superhydrophobic films and the substrate was evaluated by using a standard tape test method (D3359). The adhesion was improved by reducing the organic content in the films.

Synthesis of strong polycations with improved biological properties

“…The formation and application of such films has been reported by many authors . The systems for biomedical applications include superhydrophobic coatings, surfaces of modulated protein and cell adhesion, hollow microcapsules for drug delivery and ultrasound contrast agent carriers, nonviral transfection agents, or magnetic microgels for magnetic resonance imaging . Recently, PEMs containing PAH and various polyanions were used to prepare “active” wound care dressings.…”

Fabrication of superhydrophobic sol–gel composite films using hydrophobically modified colloidal zinc hydroxide

“…Surface modification of materials using certain compounds like long-chain fatty acids, thiols, or fluorosilanes is one such approach to reduce the surface energy of the substrates. Numerous works on the development of superhydrophobic surfaces from many materials such as polymers, silicones, and metal oxides have been reported [6][7][8][9][10]. Several techniques such as electro-deposition, chemical bath deposition, chemical etching, self-assembly/colloidal assembly, template-based techniques, sol-gel processes, and electroless galvanic deposition have been used for the preparation of superhydrophobic surfaces [11][12][13][14][15][16][17][18][19][20].…”

Adhesion strength and superhydrophobicity of polyurethane/organoclay nanocomposite coatings

“…However, the degree of adhesion between the superhydrophobic surface and the underlying substrate is a critical enabling factor for many potential applications where system conditions may quickly separate a poorly adhered surface (e.g., marine coatings and wind turbine coatings). Only recently have some researchers started to consider substrate adhesion characteristics when creating superhydrophobic nanocomposite coatings 12–15. Similarly, investigation into the mechanical durability of superhydrophobic surfaces in general is only now beginning 16…”